You ever been in a situation like that before? I tell you you don't know how you will react untill it happens to you.
It was at a fastfood joint, I'm at the other side of the cash register so I didn't see it, but all of a sudden I could hear a guy screaming "now! now!". I didn't care but my friend was looking and all of a sudden he got scared ****less and ran away, so I peeked and saw a bloody hand and the manager looking panicked and handing over the money. I didn't see it well but I thought he had a gun, so I took off.
Now I know that the robber was bloody all over his face and arms and was wielding a large axe, i **** you not. I feel really guilty for running now, considering the manager was left behind by himself with that psycho. What could I have done in that situation? What would you do?

I've been robbed before also, first paycheck from BK back in the day I went to cash it and some dude that was there followed me and didn't pull out the gun but lifted up his shirt enough so I could see the gun tucked in his pants (like ice cube in boys in the hood, "any body got a problem") and demanded my hard earning burger flipping money...I froze and gave him the money and the potato chips I had bought also...
its simple...
Your life comes first...the rest can be replaced...

I've seen muggings in my neighborhood but against outsiders. If it's nobody you know, mind your own business. Best you could do is just call the cops. If you're not made of steel, or shoot webs from your wrist, leave it alone. Leave the hero crap to cops and fighterfighters. If you know the person than help as well as you can. Only way you should try to intervene and risk your life if you don't know the person, it's if they're a child or a lady.